Imaging device, signal processing method, recording medium, and program

ABSTRACT

The present invention relates to an image-capturing apparatus, a method for processing signals, a recording medium, and a program that can improve the accuracy of an autofocus function with respect to a subject at the time of fill-light projection. A microcomputer  13  monitors a fill-light controller  15  and determines whether or not a fill-light projection flag is ON. If it is determined that the fill-light projection flag is ON, the microcomputer  13  performs computation of the amount of control of image-blur correction to determine the amount of control of image-blur correction, and outputs the determined amount of control of image-blur correction to a detector  121 . The detector  121  determines the position of a detection frame for autofocus, changes the size or number of detection frames based on information on the zoom factor, and controls the position of the detection frame, and the size or number of detection frames. The present invention is applicable to camcorders.

TECHNICAL FIELD

The present invention relates to image-capturing apparatuses, methodsfor processing signals, recording media, and programs. Specifically, thepresent invention relates to an image-capturing apparatus, a method forprocessing signals, a recording medium, and a program that can alwaysimprove the accuracy of autofocus.

BACKGROUND ART

In an image-capturing apparatus, such as a video recorder with a camera(hereinafter, referred to as camcorder) and a digital still camera,image blur is corrected, for example, by mechanically adjusting theoptical system. Such a method is typified by an “antivibrationlens-shifting method” where a shiftable lens is moved according to theamount of image blur, and a “vari-angle prism (VAP) method” where avari-angle prism is tilted according to the amount of image blur.

In such a method for correcting image blur, image-blur signals in theimage-capturing apparatus are detected, for example, by anangular-velocity sensor. Then, computations, such as integration, areperformed on the detected signals to determine the target value forimage-blur correction. Correction of the optical system is thuscontrolled such that image blur is corrected based on this target value.

On the other hand, image-capturing apparatuses incorporate an autofocusfunction to automatically focus on the subject to be captured. In theautofocus function, image contrast is detected based on the light fromthe subject. Optical lenses are then adjusted to maximize the contrast.In such an autofocus function, focus control is difficult to performunder low-light conditions or when the subject itself has a lowcontrast. Therefore, a fill-light projector, including a light, which isinstalled in the image-capturing apparatus projects a projection patternonto the subject. The autofocus function performs control to maximizethe contrast of the projection pattern projected onto the subject.

However, when the image-blur correcting function described above and theautofocus function at the time of fill-light projection aresimultaneously used, the image-blur correcting function performs controlto prevent image blur with respect to the subject, thereby causing imageblur in the projection pattern, which is projected by the fill-lightprojector installed in the image-capturing apparatus, with respect tothe optical system in the image-capturing apparatus. This image blur maycause the fill-light projection pattern to move into and out of adetection frame defining a contrast detection range for autofocus, ormay cause the projection pattern to deviate from the detection frame.

Moreover, in an image-capturing apparatus having a zoom function, thedistance between portions of the fill-light projection pattern iswidened at high zoom factors and the projection pattern may becompletely off the detection frame, even though the projection patternfalls within the detection frame at low zoom factors.

To prevent such cases, a step is provided, in the manufacturing process,for adjusting the fill-light emitting position such that the fill-lightprojection pattern falls within the detection frame at the highest zoomfactor. However, when image blur is corrected by the image-blurcorrecting function, the fill-light projection pattern simultaneouslyswings and may be completely off the detection frame.

Possible measures include increasing the pattern density of theprojection pattern, making the density of the projection patternvariable according to the zoom factor, and moving the projection patternin the same direction as that of the image-blur correction. However, inthe case where the fill-light projector includes a light source, such aslaser light, having a high energy density that involves control ofintensity and pattern density, increasing the pattern density of theprojection pattern or making the density of the projection patternvariable according to the zoom factor is difficult because of safetyconcerns. In addition, the image-capturing apparatus has structuralconstraints in moving the projection pattern in the same direction asthat of the image-blur correction and may require additionalapparatuses.

A method for solving these problems is to stop the image-blur correctingfunction during the projection of fill light. A problem in this methodis that no image-blur correction is performed during the projection offill light. Moreover, stopping the image-blur correcting function isaccompanied by noise or vibration in the image-capturing apparatus. Eventhough the image-blur correcting function is restarted after thecompletion of the fill-light projection such that the effect of theimage-blur correction at the time of exposure of images can be obtained,there is a delay until the effect of the correction becomes evident.However, control for preventing such delay causes the occurrence ofnoise or vibration.

As described above, the accuracy of the autofocus function is degradedwhen the image-blur correcting function and the autofocus function atthe time of fill-light projection are simultaneously used.

Moreover, since autofocus does not effectively work, at the time offill-light projection, when fill light is projected onto a subject thatis not suitable for the fill light (that is, for example, a subjectabsorbing the fill light, allowing the fill light to pass through, orplaced in an area, such as the end of the screen, where no fill lightreaches), the autofocus may be performed based on information on imagesobtained by light other than the projection pattern. If the image-blurcorrecting function is stopped in this case, the accuracy of theautofocus function performed based on information on images obtained bylight other than the projecting pattern, through the effective use ofthe image-blur correcting function, and the accuracy of other functions,such as exposure control and color control, are degraded.

DISCLOSURE OF INVENTION

The present invention was made in view of the circumstances describedabove, and aims to always improve the accuracy of the autofocusfunction.

An image-capturing apparatus of the present invention includes firstdetermining means determining whether or not a projection pattern isprojected by projecting means; computing means computing, based on acoefficient corresponding to the amplitude of signals detected bysensing means, the amount of image-blur correction control correspondingto the signals if the first determining means determines that theprojection pattern is projected; frame-setting means setting, based onthe amount of control computed by the computing means, the position of adetection frame within which the projection pattern is detected bydetecting means; and correction-control means controlling, based on theamount of control computed by the computing means, image-blur correctionperformed by correcting means.

The image-capturing apparatus of the present invention may furtherinclude changing means changing the size of the detection frame ornumber of detection frames based on information on the zoom factor, assoon as the position of the detection frame is set by the frame-settingmeans.

The image-capturing apparatus of the present invention may furtherinclude reference-value setting means setting a reference value; seconddetermining means determining, if the first determining means determinesthat the projection pattern is projected, whether or not the frequencyof the signals detected by the sensing means is lower than the referencevalue set by the reference-value setting means; and prohibiting meansprohibiting the image-blur correction by the correcting means if thesecond determining means determines that the frequency of the signals islower than the reference value.

The computing means may compute, if the second determining meansdetermines that the frequency of the signals is higher than thereference value, the amount of image-blur correction controlcorresponding to the signals, based on a coefficient corresponding tothe amplitude of the signals.

The computing means may compute, if the second determining meansdetermines that the frequency of the signals is higher than thereference value, the amount of image-blur correction controlcorresponding to the signals, while bringing the coefficient close to 1.

The image-capturing apparatus of the present invention may furtherinclude dividing means dividing, when the first determining meansdetermines that the projection pattern is projected, the signals into aplurality of frequency bands, based on the frequency of the signalsdetected by the sensing means; and frequency-specific computing meanscomputing the amount of image-blur correction control corresponding tothe signals divided into the plurality of frequency bands by thedividing means, for each of the frequency bands, based on thecoefficient corresponding to the amplitude of the signals. Thecorrection-control means may control, based on the amount of controlcomputed by the frequency-specific computing means, the image-blurcorrection performed by the correcting means.

The dividing means may divide the signals into three frequency bands.The frequency-specific computing means may compute the amount ofimage-blur correction control corresponding to the signals, which aredivided by the dividing means, in the lowest frequency band, whilebringing the coefficient close to 0; compute the amount of image-blurcorrection control corresponding to the signals, which are divided bythe dividing means, in the middle frequency band, based on thecoefficient corresponding to the amplitude of the signals; and computethe amount of image-blur correction control corresponding to thesignals, which are divided by the dividing means, in the highestfrequency band, while bringing the coefficient close to 1.

A method for processing signals according to the present inventionincludes a determining step for determining whether or not a projectionpattern is projected by projecting means; a computing step forcomputing, based on a coefficient corresponding to the amplitude ofsignals detected by sensing means, the amount of image-blur correctioncontrol corresponding to the signals, if it is determined in thedetermining step that the projection pattern is projected; aframe-setting step for setting, based on the amount of control computedin the computing step, the position of a detection frame within whichthe projection pattern is detected by detecting means; and acorrection-control step for controlling, based on the amount of controlcomputed in the computing step, image-blur correction performed bycorrecting means.

A program in a recording medium according to the present inventionincludes a determining step for determining whether or not a projectionpattern is projected by projecting means; a computing step forcomputing, based on a coefficient corresponding to the amplitude ofsignals detected by sensing means, the amount of image-blur correctioncontrol corresponding to the signals, if it is determined in thedetermining step that the projection pattern is projected; aframe-setting step for setting, based on the amount of control computedin the computing step, the position of a detection frame within whichthe projection pattern is detected by detecting means; and acorrection-control step for controlling, based on the amount of controlcomputed in the computing step, image-blur correction performed bycorrecting means.

A program according to the present invention includes a determining stepfor determining whether or not a projection pattern is projected byprojecting means; a computing step for computing, based on a coefficientcorresponding to the amplitude of signals detected by sensing means, theamount of image-blur correction control corresponding to the signals, ifit is determined in the determining step that the projection pattern isprojected; a frame-setting step for setting, based on the amount ofcontrol computed in the computing step, the position of a detectionframe within which the projection pattern is detected by detectingmeans; and a correction-control step for controlling, based on theamount of control computed in the computing step, image-blur correctionperformed by correcting means.

According to the present invention, if it is determined that aprojection pattern is projected, the amount of image-blur correctioncontrol corresponding to signals is computed, based on based on acoefficient corresponding to the amplitude of the detected signals.Then, the position of a detection frame within which the projectionpattern is detected is set, based on the determined amount of control,and image-blur correction is controlled, based on the determined amountof control.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing an example of the structure of animage-capturing apparatus to which the present invention is applied.

FIG. 2 is a block diagram showing an example of the structure of amicrocomputer in FIG. 1.

FIG. 3 is a block diagram showing an example of the detailed structureof an integrating processor in FIG. 2.

FIG. 4 is a diagram showing a coefficient table.

FIG. 5 is a flowchart showing fill-light projection processing in theimage-capturing apparatus in FIG. 1.

FIG. 6 is a flowchart showing image-blur correction processing in theimage-capturing apparatus in FIG. 1.

FIG. 7 is a flowchart showing computations of the amount of correctioncontrol in step S26 in FIG. 6.

FIG. 8 is a block diagram showing another example of the structure ofthe microcomputer in FIG. 1.

FIG. 9 is a diagram showing frequency bands of band-pass filters in FIG.8.

FIG. 10 is a flowchart showing another example of image-blur correctionprocessing in the image-capturing apparatus in FIG. 1.

FIG. 11 is a flowchart showing computations of the amount of correctioncontrol for respective frequency bands in step S83 in FIG. 10.

FIG. 12 is a block diagram showing another example of the structure ofthe image-capturing apparatus in FIG. 1.

FIG. 13 is a block diagram showing an example of the structure of amicrocomputer in FIG. 12.

FIG. 14 is a flowchart showing fill-light projection processing in theimage-capturing apparatus in FIG. 12.

FIG. 15 is a flowchart showing image-blur correction processing in theimage-capturing apparatus in FIG. 12.

FIG. 16 is a flowchart showing computations of the amount of control ofimage-blur correction in step S223 in FIG. 15.

FIG. 17 is a flowchart showing another example of computations of theamount of control of image-blur correction in step S223 in FIG. 15.

FIG. 18 is a block diagram showing another example of the structure ofthe image-capturing apparatus in FIG. 1.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 is a block diagram showing an example of the structure of animage-capturing apparatus 1, which is typified by a video recorder witha camera (hereinafter, referred to as camcorder), to which the presentinvention is applied. Referring to FIG. 1, the image-capturing apparatus1 includes a blur detector 11, a signal processor 12, a microcomputer13, an exposure controller 14, a fill-light controller 15, a correctioncontroller 16, and a blur corrector 17.

The blur detector 11 includes, for example, an angular-velocity sensor,which vibrates together with an optical system (not shown) and isinstalled in the image-capturing apparatus 1, and detects image blur.

The signal processor 12 receives image-blur signals, which areangular-velocity signals detected by the blur detector 11, and convertsthe image-blur signals into signals matching the interface of themicrocomputer 13. The signal processor 12 is an analog circuit includinga low-pass filter 31 blocking frequencies higher than a predeterminedcutoff frequency, an amplifier 32 amplifying image-blur signals, and ahigh-pass filter 33 blocking frequencies lower than a predeterminedcutoff frequency.

The exposure controller 14 measures the amount of light from a subject,adjusts the aperture and shutter speed, and controls the exposure and soon. The fill-light controller 15 turns ON/OFF a fill-light projectionflag based on the information on the amount of light measured by theexposure controller 14, controls a fill-light projector (not shown)including a light, and projects a fill-light projection pattern.

Based on the fill-light projection flag in the fill-light controller 15,the microcomputer 13 performs predetermined adjustment processing on theimage-blur signals from the signal processor 12 and determines theamount of control of image-blur correction corresponding to theimage-blur signals and required to correct image blur.

The correction controller 16, based on the amount of control ofimage-blur correction determined by the microcomputer 13, controls theblur corrector 17 including a motor to be positioned at a targetposition. The correction controller 16 includes a comparator 34comparing image-blur signals to the amount of control of image-blurcorrection, an adder-subtracter 35 performing addition and subtractionof control signals and the like, a low-pass filter 36 blockingfrequencies higher than a predetermined cutoff frequency, an amplifier37 amplifying signals, and a high-pass filter 38 blocking frequencieslower than a predetermined cutoff frequency.

Although the image-capturing apparatus 1 has the structure for capturingimages and the various structures for recording and playing backcaptured video signals, they are omitted from the example in FIG. 1 forconvenience of description.

FIG. 2 is a block diagram showing an example of the detailed structureof the microcomputer 13.

The microcomputer 13 includes an analog-to-digital (A/D) converter 51, ahigh-pass filter 52, a sensitivity adjuster 53, a zoom adjuster 54, anintegrating processor 55, and a modulator 56, and controls the entireoperation of the image-capturing apparatus 1. Moreover, themicrocomputer 13 sets a frequency higher than a predetermined cutofffrequency for the high-pass filter 52 as a reference value α.

The A/D converter 51 converts the image-blur signals, which are analogsignals, supplied from the signal processor 12 into digital signals andoutputs them to the high-pass filter 52. The high-pass filter 52 notonly blocks frequencies lower than a predetermined cutoff frequency, butalso, under the control of the microcomputer 13 monitoring a fill-lightprojection flag of the fill-light controller 15, blocks frequencieslower than the reference value α set as a frequency higher than apredetermined cutoff frequency, in order that no image-blur correctionto image-blur signals at such blocked frequencies is performed.

To compensate for variation in sensitivity of the angular-velocitysensor included in the blur detector 11, the sensitivity adjuster 53performs gain adjustment of the image-blur signals from the high-passfilter 52, according to the sensitivity of the angular-velocity sensor.Then, the zoom adjuster 54 performs gain adjustment of the image-blursignals, according to the zoom position.

The integrating processor 55 integrates the image-blur signals after thesensitivity adjustment and the gain adjustment and determines the amountof image-blur correction control corresponding to the image-blur signalsand required for correcting image blur. The modulator 56 converts thedetermined amount of control into pulse width modulation (PWM) signalsand outputs them to the correction controller 16.

FIG. 3 is a block diagram showing an example of the detailed structureof the integrating processor 55. In the example shown in FIG. 3, theintegrating processor 55 includes a delay device 72, a multiplier 73,and an adder 74.

The integrating processor 55 integrates the image-blur signals inputtedfrom the zoom adjuster 54 and outputs a feedback amplitude A, which isthe result of the integration, to the delay device 72. The delay device72 delays the feedback amplitude A by one sampling period. Themultiplier 73 multiplies the feedback amplitude A, which is delayed byone sampling period by the delay device 72, by a feedback coefficient Kthat can be determined based on a coefficient table such as that shownin FIG. 4.

This feedback coefficient K is a value ranging from 0 to 1. As thisfeedback coefficient K approaches 1, the effect of image-blur correctionincreases (or is intensified). However, a limit of this correction isreached, due to constrains of valid pixels, optical constraints, orstructural (mechanical) constraints, and unnatural movements ofcorrected images may occur. Therefore, a feedback coefficient Kcorresponding to a feedback amplitude A is determined based on acoefficient table as that shown in FIG. 4.

In the example shown in FIG. 4, the horizontal axis indicates values ofthe feedback amplitude A, which become higher toward the right. Thevertical axis indicates values of the feedback coefficient K rangingfrom 0 to 1. That is, this example of a coefficient table shows that thefeedback coefficient K approaches 1 as the feedback amplitude Adecreases, while the feedback coefficient K approaches 0 as the feedbackamplitude A increases.

Since the feedback coefficient K corresponding to the feedback amplitudeA can be determined as described above, the effect of image-blurcorrection increases as the feedback amplitude A decrease, while theeffect of image-blur correction decreases as the feedback amplitude Aincreases. Thus, unnatural movements of corrected images can be avoided.

The multiplier 73 multiplies the feedback amplitude A by the feedbackcoefficient K determined as described above. Then the adder 74 adds thismultiplied value to the next image-blur signals to determine the amountof control of image-blur correction for image-blur signals, and outputsthe amount of control to the modulator 56. In other words, the adder 74adds a value determined by multiplying an integrated output (feedbackamplitude A) in the previous sampling period by the feedback coefficientK, to the current image-blur signals. This processing repeats as long asimage-blur correction continues.

Processing of fill-light projection in autofocus will now be describedwith reference to the flowchart in FIG. 5.

After the power is turned on, the processing of fill-light projection isperformed in the image-capturing apparatus 1. In step S1, the fill-lightcontroller 15 obtains measured information on light from a subject, fromthe exposure controller 14.

In step S2, the fill-light controller 15 determines, based on theinformation on light from the subject, whether or not the light is lowcontrast or low intensity. If it is determined that the light is lowcontrast or low intensity, the fill-light controller 15 turns ON thefill-light projection flag in step S3.

In step S4, the fill-light controller 15 controls the fill-lightprojector (not shown) including the light to project a fill-lightprojection pattern. Thus, autofocus processing at the time of fill-lightprojection is performed in the image-capturing apparatus 1. Thisautofocus processing is performed by detecting the contrast of an imagebased on light from the subject, and by correcting an optical lens tomaximize the contrast. The projection of the fill-light projectionpattern repeats until the fill-light controller 15 determines, in stepS5, that the autofocus processing in the image-capturing apparatus 1 iscompleted.

If it is determined in step S5 that the autofocus processing in theimage-capturing apparatus 1 has been completed, the fill-lightcontroller 15 turns OFF the fill-light projection flag in step S6 andterminates the projection of the fill-light projection pattern in stepS7.

In step S2, if it is not determined that the light is low contrast andlow intensity, the fill-light controller 15 turns OFF the fill-lightprojection flag and terminates the processing in step S8.

The microcomputer 13 can determine, by monitoring the ON/OFF state ofthe fill-light projection flag in the fill-light controller 15, whetheror not the fill-light projection pattern is projected in image-blurcorrection processing described below.

The image-blur correction processing will now be described withreference to the flowchart in FIG. 6.

In step S21, the A/D converter 51 converts the image-blur signals, whichare analog signals, into digital signals.

In step S22, the microcomputer 13 monitors the fill-light controller 15and determines whether or not the fill-light projection flag is ON. Ifit is determined that the fill-light projection flag is ON, themicrocomputer 13 sets a reference value α for frequencies in step S23.The reference value α is set higher than a cutoff frequencypredetermined for the high-pass filter 52 to block low frequencies, inorder that no image-blur correction to image blur at low frequencies,which is a major cause of the movement of the projection pattern intoand out of a detection frame defining a contrast detection range for theautofocus function, is performed.

In step S24, the microcomputer 13 determines whether or not theimage-blur signals include frequency components lower than the referencevalue α set in step S23. If it is determined in step S24 that theimage-blur signals include frequency components lower than the referencevalue α, the high-pass filter 52 blocks the frequency components lowerthan the reference value α of the image-blur signals, in step S25. Thisprohibits the image-blur correction to image-blur signals at frequencieslower than the reference value α.

If it is determined in step S24 that the image-blur signals include nofrequency component lower than the reference value α, the microcomputer13 skips processing in step S25 and performs computations of the amountof correction control, in step S26. That is, in step S26, only acomputation of the amount of control of the image-blur correction toimage-blur signals at frequencies higher than the reference value α isperformed. This computation of the amount of correction control will nowbe described with reference to the flowchart in FIG. 7.

In step S41, the sensitivity adjuster 53 performs gain adjustment of theimage-blur signals according to the angular-velocity sensor included inthe blur detector 11, while the zoom adjuster 54 performs gainadjustment of the image-blur signals according to the zoom position.

In step S42, the integrating processor 55 adds the sum of a value(feedback amplitude A) determined by integrating image-blur signals inthe previous sampling period and a feedback coefficient K determinedfrom the coefficient table (see FIG. 4) to the adjusted image-blursignals, thereby determining the amount of control of the image-blurcorrection required for correcting image blur.

In step S43, the modulator 56 converts the amount of control of theimage-blur correction into pulse width modulation (PWM) signals andoutputs them to the correction controller 16.

On the other hand, if it is determined in step S22 that the fill-lightprojection flag is OFF, the high-pass filter 52 blocks, in step S27,image-blur signals at frequencies lower than a predetermined cutofffrequency. Therefore, in this case, processing subsequent to step S28 isalso performed with respect to frequency components lower than areference value α and higher than a cutoff frequency.

In step S28, the microcomputer 13 performs a normal computation of theamount of correction control. This computation of the amount ofcorrection control is basically the same as that described above withreference to FIG. 7. While the description will be omitted to avoidrepetition, this processing determines the amount of control of theimage-blur correction required for correcting image blur.

After the amount of control of the image-blur correction required forcorrecting image blur is determined in the processing in step S26 orS28, the correction controller 16 controls, in step S29, the correctionof the blur corrector 17, based on the determined amount of control ofthe image-blur correction, such that the blur corrector 17 is positionedat a target position.

In general, image-blur at high frequencies is small in amplitude and isunlikely to easily reach a limit that causes unnatural movements ofcorrected images (as described above, with reference to FIG. 4).Therefore, the feedback coefficient K may be brought close to 1 inperforming computations of the amount of correction control in step S26in FIG. 6. Thus, intensive correction only to image blur at highfrequencies can be performed at the time of fill-light projection.

Thus, the accuracy of the autofocus function is improved since, asdescribed above, correction to image blur at low frequencies, which is amajor cause of the movement of the projection pattern into and out ofthe detection frame defining a contrast detection range for theautofocus function, is prohibited. Moreover, the fill-light projectionpattern can fall within the detection frame, which is the contrastdetection range, regardless of the zoom factor.

Furthermore, since the image-blur correction with respect to highfrequencies is performed at the time of fill-light projection, normalautofocus of a subject with light other than the fill-light projectionpattern can be performed. The autofocus function can also be effectivelyperformed on a subject unsuitable for the fill light (that is, forexample, a subject absorbing the fill light, allowing the fill light topass through, or placed in an area, such as the end of the screen, whereno fill light reaches). Other controls, such as exposure control andcolor control, are also effectively performed.

Moreover, since no abrupt change of image-blur correction, such asstopping of the image-blur correcting function, is made at the time offill-light projection, the occurrence of noise, vibration, or an abruptchange of the screen can be prevented. Furthermore, since the image-blurcorrecting function always operates, a delay in image-blur correctioncan be prevented. In addition, power saving can be achieved since theimage-blur correction at the time of fill-light projection is performedwith respect to high frequencies only. Moreover, cost reduction can beachieved since the existing image-capturing apparatus requires noadditional apparatuses to realize the above-described effects.

Furthermore, in an image-capturing apparatus with a fill-light projectorincorporating a light source having a high energy density, such as laserlight, the applicability of the apparatus is improved since no changethat involves risk, such as a change in projection pattern, is requiredin the case of replacing the existing lens with a lens having adifferent zoom factor.

Although the angular-velocity sensor and angular-velocity signals havebeen used to describe the blur detector 11 and image-blur signals,respectively, other angular sensors, angular-velocity sensors, orvelocity sensors may also be employed. Moreover, although theantivibration shiftable lens is used to describe the blur corrector 17,a vari-angle prism (VAP) or the like may also be employed.

In the above description, a high reference value serving as a cutofffrequency is set in the high-pass filter 52 within the microcomputer 13.However, for example, a high reference value serving as a cutofffrequency may be set in the high-pass filter 33 within the signalprocessor 12 in FIG. 1, or in the high-pass filter 38 within thecorrection controller 16. Furthermore, frequency characteristics of theangular-velocity sensor included in the blur detector 11 may be changed.Even if, as described above, frequency characteristics are controlledoutside the microcomputer 13, image-blur correction processing ofimage-blur signals are performed according to the control of themicrocomputer 13.

FIG. 8 is a block diagram showing another example of the structure of amicrocomputer. A microcomputer 91 in FIG. 8 has the same structure asthat of the microcomputer 13 in FIG. 2 except that the high-pass filter52 is replaced with band-pass filters 101 to 103. Componentscorresponding to those in FIG. 2 are indicated by the same referencenumerals and the description will be omitted to avoid repetition.

The band-pass filters 101 to 103 subsequent to the A/D converter 51 arearranged in parallel, allow image-blur signals at respective frequencybands, which are outputted from the A/D converter 51, to pass through,and output them to the sensitivity adjuster 53. While these frequencybands are predetermined, as shown in FIG. 9, they may be controlled bythe microcomputer 91.

FIG. 9 is a diagram showing frequency bands corresponding to therespective band-pass filters 101 to 103. In FIG. 9, the horizontal axisindicates frequencies which become higher toward the right. The verticalaxis indicates the ratio of signals outputted from each of the band-passfilters 101 to 103.

In the case of the example shown in FIG. 9, the lowest frequency band E1ranging from a frequency a to a frequency c (the frequency band thatincludes the lowest frequencies in frequency bands E1 to E3) is thefrequency band that can be passed by the band-pass filter 101, themiddle frequency band E2 ranging from a frequency b to a frequency d(the frequency band that includes the middle frequencies in frequencybands E1 to E3) is the frequency band that can be passed by theband-pass filter 102, and the highest frequency band E2 ranging from afrequency d to a frequency f (the frequency band that includes thehighest frequencies in frequency bands E1 to E3) is the frequency bandthat can be passed by the band-pass filter 103 (0<a<b<c<d<e<<f).

Although the frequency band ranging from the frequency b to thefrequency c overlaps with the frequency band E1 and the frequency bandE2, this poses no problem since the frequency band ranging from thefrequency b to the frequency c is narrow. Similarly, although thefrequency band ranging from the frequency d to the frequency e overlapswith the frequency band E2 and the frequency band E3, this poses noproblem since the frequency band ranging from the frequency d to thefrequency e is narrow.

The microcomputer 91 controls the integrating processor 55 to determinethe amount of control of image-blur correction based on signals in thelowest frequency band E1 that are passed through the band-pass filter101, signals in the middle frequency band E2 that are passed through theband-pass filter 102, and signals in the highest frequency band E3 thatare passed through the band-pass filter 103.

Another example of image-blur correction processing will now bedescribed with reference to the flowchart in FIG. 10.

In step S81, the A/D converter 51 converts the image-blur signals, whichare analog signals, into digital signals.

In step S82, the microcomputer 91 monitors the fill-light controller 15and determines whether or not the fill-light projection flag is ON. Ifit is determined that the fill-light projection flag is ON, themicrocomputer 91 performs computations of the amount of correctioncontrol for the respective frequency bands in step S83. The computationsof the amount of correction control for the respective frequency bandswill now be described with reference to the flowchart in FIG. 11.

In step S101, as described with reference to FIG. 9, the band-passfilters 101 to 103 pass signals in the respective frequency bands andblock signals at other frequencies. Here, the band-pass filter 101passes signals in the lowest frequency band E1, the band-pass filter 102passes signals in the middle frequency band E2, and the band-pass filter103 passes signals in the highest frequency band E3.

In step S102, the sensitivity adjuster 53 performs gain adjustment ofthe image-blur signals passed in step S101 according to theangular-velocity sensor included in the blur detector 11, while the zoomadjuster 54 performs gain adjustment of the image-blur signals accordingto the zoom position.

In step S103, the microcomputer 91 determines whether or not thefrequencies of the image-blur signals have been passed through theband-pass filter 101. That is, it is determined whether or not thefrequencies of the image-blur signals fall within the frequency band(the lowest frequency band E1 ranging from the frequency a to thefrequency c) that can be passed by the band-pass filter 101.

If it is determined, in step S103, that the frequencies of theimage-blur signals have been passed through the band-pass filter 101,the integrating processor 55 adds, in step S104, the sum of a value(feedback amplitude A) determined by integrating image-blur signals inthe previous sampling period and a feedback coefficient K close to 0 tothe adjusted image-blur signals, thereby determining the amount ofcontrol of the image-blur correction required for correcting image-blur.Thus, the image-blur correction is controlled, in the subsequentprocessing, such that the effect of image-blur correction with respectto signals at frequencies within the lowest frequency band E1 can beweakened.

If it is not determined, in step S103, that the frequencies of theimage-blur signals have been passed through the band-pass filter 101,the microcomputer 91 determines, in step S105, whether or not thefrequencies of the image-blur signals have been passed through theband-pass filter 102. That is, it is determined whether or not thefrequencies of the image-blur signals fall within the frequency band(the middle frequency band E2 ranging from the frequency b to thefrequency e) that can be passed by the band-pass filter 102.

If it is determined, in step S105, that the frequencies of theimage-blur signals have been passed through the band-pass filter 102,the integrating processor 55 adds, in step S106, the sum of a value(feedback amplitude A) determined by integrating image-blur signals inthe previous sampling period and a feedback coefficient K determinedfrom the coefficient table (see FIG. 4) to the adjusted image-blursignals, thereby determining the amount of control of the image-blurcorrection required for correcting image-blur. Thus, the image-blurcorrection is controlled, in the subsequent processing, such that normalimage-blur correction is performed with respect to signals atfrequencies within the middle frequency band E2.

If it is not determined, in step S105, that the frequencies of theimage-blur signals have been passed through the band-pass filter 102,the microcomputer 91 determines, in step S107, whether or not thefrequencies of the image-blur signals have been passed through theband-pass filter 103. That is, it is determined whether or not thefrequencies of the image-blur signals fall within the frequency band(the highest frequency band E3 ranging from the frequency d to thefrequency f) that can be passed by the band-pass filter 103.

If it is determined, in step S107, that the frequencies of theimage-blur signals have been passed through the band-pass filter 103,the integrating processor 55 adds, in step S108, the sum of a value(feedback amplitude A) determined by integrating image-blur signals inthe previous sampling period and a feedback coefficient K close to 1 tothe adjusted image-blur signals, thereby determining the amount ofcontrol of the image-blur correction required for correcting image-blur.Thus, the image-blur correction is controlled, in the subsequentprocessing, such that the effect of image-blur correction with respectto signals at frequencies within the highest frequency band E3 can beintensified.

If it is not determined, in step S107, that the frequencies of theimage-blur signals have been passed through the band-pass filter 103, noprocessing is performed since the frequencies of the image-blur signalsare blocked by all of the band-pass filters 101 to 103.

In step S109, the modulator 56 converts the amount of control ofimage-blur correction determined, in the above-described processing,corresponding to each frequency band into pulse width modulation (PWM)signals and outputs them to the correction controller 16.

On the other hand, if it is determined, in step S82, that the fill-lightprojection flag is OFF, the band-pass filters 101 to 103 allow signalsin respective predetermined frequency bands to pass through and outputthem to the sensitivity adjuster 53 in step S84.

In step S85, the microcomputer 13, with respect to the signals passedthrough any of the band-pass filters 101 to 103, performs a normalcomputation of the amount of correction control. This computation of theamount of correction control is the same as that performed in step S26in FIG. 6 (that is, in FIG. 7). While the description will be omitted toavoid repetition, this processing determines the amount of control ofthe image-blur correction required for correcting image blur.

After the amount of control of the image-blur correction required forcorrecting image blur is determined in the processing in step S83 orS85, the correction controller 16 controls, in step S86, the correctionof the blur corrector 17, based on the determined amount of control ofthe image-blur correction, such that the blur corrector 17 is positionedat a target position.

As described above, since the amount of control of image-blur correctioncorresponding to each frequency band can be determined, image-blurcorrection can be made such that the effect of correction to image blurat high frequencies can be intensified, or, at the time of fill-lightprojection, the effect of correction to image blur at low frequenciescan be weakened, such correction being a major cause of the movement ofthe projection pattern into and out of the detection frame defining acontrast detection range for the autofocus function. In this case, othercontrols, such as exposure control and color control, are performed moreeffectively, compared to the case where no image-blur correction isperformed.

Although three band-pass filters are arranged in parallel in the abovedescription, the number of band-pass filters is not limited to three.Any number of band-pass filters required to separate the frequency bandsmay be arranged in parallel.

As described above, the image-blur correcting function is controlledsuch that, at the time of fill-light projection, no correction to imageblur at low frequencies is performed, such correction being a majorcause of the movement of the projection pattern into and out of thedetection frame defining a contrast detection range for the autofocusfunction. However, the control of the image-blur correcting function isstill accompanied by noise or vibration in this method, while theirlevels are lower compared to the case where the operation of stoppingthe image-blur correcting function is performed. Moreover, sinceimage-blur correction is made to image blur at high frequencies in thiscase, the fill-light projection pattern may shift out of the detectionframe at high frequencies. Other image-blur correcting functionperformed to cope with the above-described problems will now bedescribed.

FIG. 12 is a block diagram showing an example of another structure ofthe image-capturing apparatus 1 to which the present invention isapplied. In FIG. 12, components corresponding to those in FIG. 1 areindicated by the same reference numerals and the description will beomitted to avoid repetition. Referring to FIG. 12, an image-capturingapparatus 1 includes a detector 121 and a focus controller 122, as wellas a blur detector 11, a signal processor 12, a microcomputer 13, anexposure controller 14, a fill-light controller 15, a correctioncontroller 16, and a blur corrector 17.

The detector 121 determines the position (coordinates) of a detectionframe based on the amount of control of image-blur correction determinedby the microcomputer 13, determines the size or number of detectionframes based on information on the zoom factor, controls the position,controls the size or number of detection frames based on the determinedvalues, and performs detection for autofocus within the detection frame.This detection frame is a contrast detection range used, in autofocus,to detect the contrast of images based on light from a subject.

The focus controller 122 performs autofocus based on the informationdetected by the detector 121, and outputs the information indicating thecompletion of autofocus to the fill-light controller 15.

FIG. 13 is a block diagram showing an example of the detailed structureof the microcomputer 13. In FIG. 13, components corresponding to thosein FIG. 2 are indicated by the same reference numerals and thedescription will be omitted to avoid repetition.

The microcomputer 13 includes an analog-to-digital (A/D) converter 51, ahigh-pass filter 52, a sensitivity adjuster 53, a zoom adjuster 54, anintegrating processor 55, and a modulator 56 and controls the entireoperation of the image-capturing apparatus 1.

The A/D converter 51 converts image-blur signals, which are analogsignals, from the signal processor 12 into digital signals and outputsthem to the high-pass filter 52. The high-pass filter 52 blocksfrequencies lower than a predetermined cutoff frequency.

To compensate for variation in sensitivity of an angular-velocity sensorincluded in the blur detector 11, the sensitivity adjuster 53 detectsthe sensitivity of the angular-velocity sensor and performs gainadjustment of the image-blur signals from the high-pass filter 52,according to the sensitivity of the angular-velocity sensor. Then, thezoom adjuster 54 detects the zoom factor and performs gain adjustment ofthe image-blur signals according to the zoom factor. Furthermore, thezoom adjuster 54 outputs the detected zoom factor to the detector 121.

The integrating processor 55 integrates the image-blur signals after thesensitivity adjustment and the gain adjustment, determines the amount ofimage-blur correction control corresponding to the image-blur signalsand required for correcting image blur, and outputs the determinedamount of control to the detector 121 or the modulator 56. The modulator56 converts the determined amount of control into pulse width modulation(PWM) signals and outputs them to the correction controller 16.

Processing of fill-light projection in autofocus will now be describedwith reference to the flowchart in FIG. 14.

After the power is turned on, the processing of fill-light projection isperformed in the image-capturing apparatus 1. In step S201, thefill-light controller 15 obtains measured information on light from asubject, from the exposure controller 14.

In step S202, the fill-light controller 15 determines, based on theinformation on light from the subject, whether or not the light is lowcontrast or low intensity. If it is determined that the light is lowcontrast or low intensity, the fill-light controller 15 turns ON thefill-light projection flag in step S203.

In step S204, the fill-light controller 15 controls the fill-lightprojector (not shown) including the light to project a fill-lightprojection pattern. Thus, in step S205, the detector 121 and the focuscontroller 122 perform autofocus processing at the time of fill-lightprojection.

This autofocus processing is performed by the detector 121, whichdetects the contrast of an image based on light from the subject, withina detection range defined based on the amount of control of image-blurcorrection, and by the focus controller 122, which corrects an opticallens to maximize the contrast. The position, and the size or number ofthe detection frames are determined, in image-blur correction processingdescribed below with reference to the flowchart in FIG. 15, by thedetector 121, based on the amount of image-blur correction controlsupplied from the integrating processor 55.

On completion of the autofocus processing in step S205, the focuscontroller 122 outputs information indicating the completion of theautofocus processing to the fill-light controller 15. In response, instep S206, the fill-light controller 15 determines whether or not theautofocus processing has been completed. If it is not determined thatthe autofocus processing has been completed, the process returns to stepS204 and repeats the subsequent processing.

If it is determined in step S206 that the autofocus processing has beencompleted, the fill-light controller 15 turns OFF the fill-lightprojection flag in step S207 and terminates the projection of thefill-light projection pattern in step S208.

In step S202, if it is not determined that the light is low contrast orlow intensity, the fill-light controller 15 turns OFF the fill-lightprojection flag and terminates the processing in step S209.

The microcomputer 13 can determine, by monitoring the ON/OFF state ofthe fill-light projection flag in the fill-light controller 15, whetheror not the fill-light projection pattern is projected in image-blurcorrection processing described below.

The image-blur correction processing will now be described withreference to the flowchart in FIG. 15.

In step S221, the A/D converter 51 converts the image-blur signals,which are analog signals, into digital signals.

In step S222, the microcomputer 13 monitors the fill-light controller 15and determines whether or not the fill-light projection flag is ON. Ifit is determined that the fill-light projection flag is ON, themicrocomputer 13 performs a computation of the amount of control ofimage-blur correction in step S223. The computation of the amount ofcontrol of image-blur correction will now be described with reference tothe flowchart in FIG. 16.

In step S241, the high-pass filter 52 blocks image-blur signals atfrequencies lower than a predetermined cutoff frequency.

In step S242, the sensitivity adjuster 53 detects the sensitivity of theangular-velocity sensor included in the blur detector 11 and performsgain adjustment of the image-blur signals according to the sensitivityof the angular-velocity sensor. The zoom adjuster 54 detects a zoomfactor and performs gain adjustment of the image-blur signals accordingto the zoom factor.

In step S243, the integrating processor 55 adds the sum of a value(feedback amplitude A) determined by integrating image-blur signals inthe previous sampling period and a feedback coefficient K determinedfrom the coefficient table (see FIG. 4) to the adjusted image-blursignals, thereby determining the amount of control of the image-blurcorrection required for correcting image blur.

Since the amount of control of image-blur correction is determined asdescribed above, the integrating processor 55 outputs the determinedamount of control of image-blur correction to the detector 121 in stepS224 in FIG. 15, while the zoom adjuster 54 outputs the information onthe zoom factor to the detector 121.

In step S225, the detector 121 determines the position of the detectionframe, based on the amount of control of image-blur correction from theintegrating processor 55, such that the detection frame moves in thedirection canceling the image-blur correction. In step S226, thedetector 121 changes the size or number of detection frames based on theinformation on the zoom factor supplied from the zoom adjuster 54. Thisprocessing for changing the size or number of detection frames isperformed to reduce the probability that the fill-light projectionpattern moves in and out of the detection frame, or that the fill-lightprojection pattern is off the detection frame.

In step S227, the detector 121 controls the detection frame based on theposition of the detection frame determined in step S225, and on the sizeor number of detection frames determined in step S226. Since the imagecontrast of the projection pattern is detected (the above-describedautofocus processing in step S205 in FIG. 14) within the detection framecontrolled as described above, based on the amount of control ofimage-blur correction, the movement of the fill-light projection patterninto and out of the detection frame can be prevented at the time ofimage-blur correction. The accuracy of the autofocus function is thusimproved.

On the other hand, if it is determined, in step S222, that thefill-light projection flag is OFF, the microcomputer 13 performs acomputation of the amount of control of image-blur correction in stepS228. This computation of the amount of correction control is the sameas that performed in step S223 (that is, in FIG. 16). While thedescription will be omitted to avoid repetition, this processingdetermines the amount of control of the image-blur correction requiredfor correcting image blur.

Then, in step S229, the modulator 56 converts the amount of theimage-blur correction control, determined by the integrating processor55 in step S223 or in S228, into pulse width modulation (PWM) signalsand outputs them to the correction controller 16.

In step S230, the correction controller 16 controls the correction ofthe blur corrector 17, based on the determined amount of control of theimage-blur correction, such that the blur corrector 17 is positioned ata target position.

At the time of fill-light projection, as described above, the positionof the detection frame defining a contrast detection range for theautofocus function is controlled based on the amount of control ofimage-blur correction. Thus, at the time of detection, the movement ofthe projection pattern into and out of the detection frame can beprevented and the accuracy of the autofocus function can be improved.Moreover, processing for changing the size or number of detection framesmakes the fill-light projection pattern to more easily enter thedetection frame regardless of the zoom factor.

The processing for changing the size or number of the detection framesis particularly effective in the case where the amount of control ofimage-blur correction is too large, for the control of the detectionframe alone, to reduce the probability that the fill-light projectionpattern moves in and out of the detection frame, or that the fill-lightprojection pattern is off the detection frame.

Furthermore, since the image-blur correction can be performed at thetime of fill-light projection, normal autofocus of a subject can beperformed with light other than the fill-light projection pattern. Theautofocus function can also be effectively performed on a subjectunsuitable for the fill light (that is, for example, a subject absorbingthe fill light, allowing the fill light to pass through, or placed in anarea, such as the end of the screen, where no fill light reaches). Othercontrols, such as exposure control and color control, are alsoeffectively performed.

Moreover, since no abrupt change of image-blur correction, such asstopping of the image-blur correcting function and changing of themethod for controlling the correcting function, is made at the time offill-light projection, the occurrence of noise, vibration, or an abruptchange of the screen can be prevented. Furthermore, since the image-blurcorrecting function always operates, a delay in image-blur correctioncan be prevented. In addition, cost reduction can be achieved since theexisting image-capturing apparatus requires no additional apparatuses torealize the above-described effects.

Furthermore, in an image-capturing apparatus with a fill-light projectorincorporating a light source having a high energy density, such as laserlight, the applicability of the apparatus is improved since no changethat involves risk, such as a change in projection pattern, is requiredin the case of replacing the existing lens with a lens having adifferent zoom factor.

The flowchart in FIG. 17 shows an example of computations of the amountof image-blur correction control in the image-capturing apparatus 1 inFIG. 12, to which control processing of the image-blur correctingfunction for not performing correction to image-blur signals at lowfrequencies during fill-light projection performed in theimage-capturing apparatus 1 in FIG. 1 is applied. This computation ofthe amount of image-blur correction control is another example of thatperformed in step S223 in the case where the microcomputer 13determines, in step S222 in FIG. 15, that the fill-light projection flagis ON.

In step S261, the microcomputer 13 sets a reference value α forfrequencies. This reference value α for frequencies is set higher than acutoff frequency predetermined for the high-pass filter 52 to block lowfrequencies, in order that no image-blur correction to image blur at thelow frequencies, which is a major cause of the movement of theprojection pattern into and out of a detection frame defining a contrastdetection range for an autofocus function, is performed.

In step S262, the microcomputer 13 determines whether or not theimage-blur signals include frequency components lower than the referencevalue a set in step S261. If it is determined, in step S262, that theimage-blur signals include frequency components lower than the referencevalue a, the high-pass filter 52 blocks the frequency components lowerthan the reference value α of the image-blur signals, in step S263. Thisprohibits a computation of the amount of control of image-blurcorrection to image-blur signals at frequencies lower than the referencevalue α.

If it is determined in step S262 that the image-blur signals include nofrequency component lower than the reference value α, the microcomputer13 skips processing in step S263 and performs a computation of theamount of correction control, in step S264. That is, in processingsubsequent to step S264, only computation of the amount of control ofthe image-blur correction to image-blur signals at frequencies higherthan the reference value α is performed.

In step S264, the sensitivity adjuster 53 performs gain adjustment ofthe image-blur signals according to the angular-velocity sensor includedin the blur detector 11, while the zoom adjuster 54 performs gainadjustment of the image-blur signals according to the zoom position.

In step S265, the integrating processor 55 adds the sum of a value(feedback amplitude A) determined by integrating image-blur signals inthe previous sampling period and a feedback coefficient K determinedfrom the coefficient table (see FIG. 4) to the adjusted image-blursignals, thereby determining the amount of control of the image-blurcorrection required for correcting image blur.

In processing subsequent to step S224 in FIG. 15, the position of thedetection frame, which is a contrast detection range for the autofocusfunction, and the image-blur correction are controlled, based on theamount of control of image-blur correction, the amount being determinedas described above. That is, since a computation of the amount ofcontrol of image-blur correction at low frequencies is prohibited, thesubsequent control of the detection frame and the image-blur correctionare performed based on the amount of control of image-blur correctiondetermined by a computation of the amount of control of image-blurcorrection at other frequencies (high frequencies).

As described above, correction to image blur at low frequencies and toimage blur due to hand movements with high amplitude, which probablycause deviation of the projection pattern from the detection frame ormovement of the projection pattern into and out of the detection frame,are restricted, while the detection frame is controlled. Thus, a largeamount of correction control that cannot be achieved only by controllingthe detection frame, for example, in the case where the fill-lightprojection pattern goes beyond the detection frame, is not performed.Thus, the movement of the fill-light projection pattern into and out ofthe detection frame can be more effectively prevented, and the accuracyof the autofocus function is improved.

Although the angular-velocity sensor and angular-velocity signals havebeen used to describe the blur detector 11 and image-blur signals,respectively, other angular sensors, angular-velocity sensors, orvelocity sensors may also be employed. Moreover, although theantivibration shiftable lens is used to describe the blur corrector 17,a vari-angle prism (VAP) or the like may also be employed.

Although the detection frame for the autofocus function has beendescribed above, detection frames for functions other than the autofocusfunction may also be controlled such that the amount of control ofimage-blur correction is cancelled.

Although the above description has focused on camcorders, the presentinvention is also applicable to digital still cameras and otherapparatuses for capturing moving images and still images.

Although the series of processing operations described above can beexecuted by hardware, it can also be executed by software. In this case,for example, the image-capturing apparatus 1 in FIG. 1 and FIG. 12 isreplaced with an image-capturing apparatus 201, as shown in FIG. 18.

Referring to FIG. 18, a central processing unit (CPU) 211 performsvarious processing according to a program stored in a read only memory(ROM) 212, or a program loaded from a memory unit 218 to a random accessmemory (RAM) 213. Data, and the like, required for the CPU 211 toperform various processing is stored in the RAM 213 as necessary.

The CPU 211, the ROM 212, and the RAM 213 are connected with one anothervia a bus 214. An input-output interface 215 is also connected to thebus 214.

An input unit 216 including a keyboard and a mouse; an output unit 217including a display, such as a cathode ray tube (CRT) and a liquidcrystal display (LCD), and a speaker; the memory unit 218 including ahard disk; and a communication unit 219 including a modem and a terminaladapter are connected to the input-output interface 215. Thecommunication unit 219 performs communication processing via a network,which is not shown.

A drive 220 is connected to the input-output interface 215, asnecessary, and is provided with, for example, a magnetic disk 221, anoptical disk 222, a magneto-optical disk 223, and a semiconductor memory224, as necessary, and computer programs read out therefrom areinstalled in the memory unit 218, as necessary.

To execute a series of processing operations by software, programsincluded in the software are installed from a network or a recordingmedium into a computer incorporated in dedicated hardware or, forexample, into a general-purpose personal computer that can performvarious functions by installation of various programs.

The recording medium not only includes a packaged medium distributedseparately from the main body of the apparatus, as shown in FIG. 18, soas to provide users with programs, and including, for example, themagnetic disk 221 (including flexible disk), the optical disk 222(including compact-disk read-only memory (CD-ROM) and digital versatiledisk (DVD)), the magneto-optical disk 223 (including Mini-Disc(registered trademark) (MD)), and the semiconductor memory 224, in whichprograms are recorded, but also includes the ROM 212 and a hard diskincluded in the memory unit 218, in which programs are recorded, andwhich are preinstalled and provided together with the main body of theapparatus to users.

In the present description, steps of describing programs to be recordedin the recording medium not only include processing performed inchronological order according to a described order, but also includeprocessing not necessarily performed in chronological order butperformed simultaneously or individually.

In the present description, system refers to the entire apparatusincluding a plurality of units.

INDUSTRIAL APPLICABILITY

As described above, according to the present invention, the accuracyimprovement of the autofocus function is enhanced. Moreover, accordingto the present invention, degradation of the accuracy of control, suchas color control and exposure control, can be prevented. Furthermore,according to the present invention, a fill-light projection pattern caneasily fall within the detection frame regardless of the zoom factor.According to the present invention, power saving and cost reduction canbe achieved.

1. An image-capturing apparatus comprising sensing means detectingsignals of image blur; correcting means correcting the image blur;projecting means projecting a projection pattern for focus processingtoward a subject to be captured; and detecting means detecting theprojection pattern within a detection frame, the pattern being projectedby the projecting means; the apparatus comprising: first determiningmeans determining whether or not the projection pattern is projected bythe projecting means; computing means computing, if the firstdetermining means determines that the projection pattern is projected,the amount of image-blur correction control corresponding to thesignals, based on a coefficient corresponding to the amplitude of thesignals detected by the sensing means; frame-setting means setting,based on the amount of control computed by the computing means, theposition of the detection frame within which the projection pattern isdetected by the detecting means; and correction-control meanscontrolling, based on the amount of control computed by the computingmeans, the correction of the image blur performed by the correctingmeans.
 2. The image-capturing apparatus according to claim 1, furthercomprising: changing means changing the size of the detection frame ornumber of detection frames based on information on the zoom factor, assoon as the position of the detection frame is set by the frame-settingmeans.
 3. The image-capturing apparatus according to claim 1, furthercomprising: reference-value setting means setting a reference value;second determining means determining, if the first determining meansdetermines that the projection pattern is projected, whether or not thefrequency of the signals detected by the sensing means is lower than thereference value set by the reference-value setting means; andprohibiting means prohibiting the image-blur correction by thecorrecting means if the second determining means determines that thefrequency of the signals is lower than the reference value.
 4. Theimage-capturing apparatus according to claim 3, wherein the computingmeans computes, if the second determining means determines that thefrequency of the signals is higher than the reference value, the amountof image-blur correction control corresponding to the signals, based ona coefficient corresponding to the amplitude of the signals.
 5. Theimage-capturing apparatus according to claim 4, wherein the computingmeans computes, if the second determining means determines that thefrequency of the signals is higher than the reference value, the amountof image-blur correction control corresponding to the signals, whilebringing the coefficient close to
 1. 6. The image-capturing apparatusaccording to claim 1, further comprising: dividing means dividing, whenthe first determining means determines that the projection pattern isprojected, the signals into a plurality of frequency bands, based on thefrequency of the signals detected by the sensing means; andfrequency-specific computing means computing the amount of image-blurcorrection control corresponding to the signals divided into theplurality of frequency bands by the dividing means, for each of thefrequency bands, based on the coefficient corresponding to the amplitudeof the signals; wherein the correction-control means controls, based onthe amount of control computed by the frequency-specific computingmeans, the correction of the image blur performed by the correctingmeans.
 7. The image-capturing apparatus according to claim 6, whereinthe dividing means divides the signals into three frequency bands; thefrequency-specific computing means computes the amount of image-blurcorrection control corresponding to the signals, which are divided bythe dividing means, in the lowest frequency band, while bringing thecoefficient close to 0; computes the amount of image-blur correctioncontrol corresponding to the signals, which are divided by the dividingmeans, in the middle frequency band, based on the coefficientcorresponding to the amplitude of the signals; and computes the amountof image-blur correction control corresponding to the signals, which aredivided by the dividing means, in the highest frequency band, whilebringing the coefficient close to
 1. 8. A method for processing signalsin an image-capturing apparatus comprising sensing means detectingsignals of image blur; correcting means correcting the image blur;projecting means projecting a projection pattern for focus processingtoward a subject to be captured; and detecting means detecting theprojection pattern within a detection frame, the pattern being projectedby the projecting means; the method comprising: a determining step fordetermining whether or not the projection pattern is projected by theprojecting means; a computing step for computing, if it is determined inthe determining step that the projection pattern is projected, theamount of image-blur correction control corresponding to the signals,based on a coefficient corresponding to the amplitude of the signalsdetected by the sensing means; a frame-setting step for setting, basedon the amount of control computed in the computing step, the position ofthe detection frame within which the projection pattern is detected bythe detecting means; and a correction-control step for controlling,based on the amount of control computed in the computing step, thecorrection of the image blur performed by the correcting means.
 9. Arecording medium for recording a computer-readable program for animage-capturing apparatus comprising sensing means detecting signals ofimage blur; correcting means correcting the image blur; projecting meansprojecting a projection pattern for focus processing toward a subject tobe captured; and detecting means detecting the projection pattern withina detection frame, the pattern being projected by the projecting means;the program comprising: a determining step for determining whether ornot the projection pattern is projected by the projecting means; acomputing step for computing, if it is determined in the determiningstep that the projection pattern is projected, the amount of image-blurcorrection control corresponding to the signals, based on a coefficientcorresponding to the amplitude of the signals detected by the sensingmeans; a frame-setting step for setting, based on the amount of controlcomputed in the computing step, the position of the detection framewithin which the projection pattern is detected by the detecting means;and a correction-control step for controlling, based on the amount ofcontrol computed in the computing step, the correction of the image blurperformed by the correcting means.
 10. A computer-readable program forcontrolling an image-capturing apparatus comprising sensing meansdetecting signals of image blur; correcting means correcting the imageblur; projecting means projecting a projection pattern for focusprocessing toward a subject to be captured; and detecting meansdetecting the projection pattern within a detection frame, the patternbeing projected by the projecting means; the program comprising: adetermining step for determining whether or not the projection patternis projected by the projecting means; a computing step for computing, ifit is determined in the determining step that the projection pattern isprojected, the amount of image-blur correction control corresponding tothe signals, based on a coefficient corresponding to the amplitude ofthe signals detected by the sensing means; a frame-setting step forsetting, based on the amount of control computed in the computing step,the position of the detection frame within which the projection patternis detected by the detecting means; and a correction-control step forcontrolling, based on the amount of control computed in the computingstep, the correction of the image blur performed by the correctingmeans.